code: def test_sentence_indices_multidoc(self, processed_multidoc):
      sentences = [
          sent for doc in processed_multidoc for sent in doc.sentences
      ]
      for sent_idx, sentence in enumerate(sentences):
          assert sent_idx == sentence.index
  
imports: import pytest
  import stanza
  from stanza.utils.conll import CoNLL
  from stanza.models.common.doc import Document
  from stanza.tests import *
  from stanza.tests.pipeline.pipeline_device_tests import check_on_gpu, check_on_cpu
label_desc: Use image node_id 16 for calling the TestEnglishPipeline obj's underlying member method code with example usage: obj.test_sentence_indices_multidoc(processed_multidoc) without return types